5.
Fig. 1. The first 3 s of GRB 130427A. Shown are composite light curves for the
three Fermi detector types (green: GBM NaI #6 [10 – 300 keV]; blue: GBM BGO
#1 [300 keV – 45 MeV]; red: LAT LLE [>20 MeV]). Each curve has been
normalized so that their peak intensities match. High probability LAT photons >
100 MeV are indicated by circles (right axis – energy in MeV). (Inset figure) Lag
analysis of the triggering pulse of GRB 130427A. Time lag τ (filled symbols) as
determined by the DCCF analysis between the (10-100 MeV) LLE lightcurve and
selected energy bands of the NaI (green) and BGO (blue) lightcurves. Also
displayed are fitted pulse widths as a function of energy W(E) (hollow symbols,
in sec.) for several energy bands. The two dashed lines represent: 1), the best-fit
2
power-law model (χ of 5.6 for 9 degrees of freedom) for W(E) (black), and 2),
the expected dependence of the time lag τ as a function of energy (red),
assuming the same power-law index as in 1).
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6.
Fig. 2. The fitted Band function Epeak (blue) and synchrotron peak energies
(red) as a function of time. The times are referenced from when the LLE light
curve peaks 0.1 s before the trigger. A broken power-law fit to the red points is
indicated by a dashed line (early time decay index of –0.4 ± 0.2, with a break at
2
0.38 ± 0.08 s, breaking to an index of –1.17 ± 0.05 with a χ = 28 for 22 degrees
of freedom). We also show the Band function Epeak values for the same time
2
intervals with a single fitted power law index (–0.96 ± 0.02 with a χ of 19 for 24
degrees of freedom).
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7.
Fig. 3. Plot showing trends in the derived photospheric Lorentz
factor (red – left axis) and radius (blue – right axis). The reference
time is the same as in Fig. 2. We obtain both values from the
instantaneous ratio of the observed blackbody component flux to the total
flux, following equations 4 and 5 in (28) and assuming a value of Y0 = 1
for the ratio between the total emitted thermal energy vs. the total energy
emitted in gamma rays.
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8.
Fig. 4. Correlation between the GRB 130427A host rest frame synchrotron
peak energy and isotropic luminosity during the rising phase (red) and
decaying phase (black) of the triggering pulse. Time progresses
approximately from right to left on the plot. The 1.43 ± 0.04 power-law index fit to
the black points is shown in green (region of uncertainty in gray), while the 3/2
power-law from the magnetic flux-freezing calculation in the text is indicated in
blue.
/ http://www.sciencemag.org/content/early/recent / 21 November 2013 / Page 8/ 10.1126/science.1242302